Hithertofore, a variety of collapsible baby carriages has been proposed and practically employed. Some of the prior art baby carriages of the type are shown, for example, in U.S. Pat. Nos. 4,007,947, 4,132,429, 4,248,443 and 4,353,577, Japanese Laid-Open Patent Application Nos. 63555/81 and 128267/81 and Japanese Laid-Open Utility Model Application No. 138765/81. However, all of the prior art baby carriages require substantial time and effort when collapsing or folding the carriage from its operative or unfolded condition to its collapsed condition and the folding or unfolding of the carriage in a limited space such as the porch of a residence is difficult. Additionally, if the locking device on the prior art baby carriage inadvertently unlocks, there is a possibility of the baby lying in the carriage falling hazardously. Furthermore, when the front wheels of the prior art baby carriages are not provided with casters, it is impossible to positively maintain the wheels in their intended orientation or the steering of the front wheels is not satisfactory.
That is, in the prior art baby carriages, since the front wheels are mounted on stationary axles, the front wheels need to be forced to change their orientation and to overcome the ground resistance which the wheels encounter when being turned in this way and manipulation of the carriage thus requires substantial effort. Thus, the prior art baby carriages have the disadvantage that the side faces of the front wheels prematurely wear away to a substantial degree.